131665691 has 2 divisors, whose sum is σ = 131665692. Its totient is φ = 131665690.

The previous prime is 131665673. The next prime is 131665693. The reversal of 131665691 is 196566131.

It is a happy number.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 131665691 - 2¹⁴ = 131649307 is a prime.

Together with 131665693, it forms a pair of twin primes.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (131665693) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 65832845 + 65832846.

It is an arithmetic number, because the mean of its divisors is an integer number (65832846).

Almost surely, 2^131665691 is an apocalyptic number.

131665691 is a deficient number, since it is larger than the sum of its proper divisors (1).

131665691 is an equidigital number, since it uses as much as digits as its factorization.

131665691 is an evil number, because the sum of its binary digits is even.

The product of its digits is 29160, while the sum is 38.

The square root of 131665691 is about 11474.5671378052. The cubic root of 131665691 is about 508.7341295832.

The spelling of 131665691 in words is "one hundred thirty-one million, six hundred sixty-five thousand, six hundred ninety-one".